@article{article276709cb,
title   = {Color tunability of intense upconversion emission from Er3+ –Yb3+ co-doped SiO2–Ta2O5 glass ceramic planar waveguides},
author = {Ferrari, Jefferson Luis and Lima, Karmel de Oliveira and Pecoraro, Edison and Ferreira, Rute A. S. and Carlos, Luís D. and Gonçalves, Rogéria Rocha},
year = {2012},
doi = {10.1039/c2jm30456b},
journal   = {Journal of Materials Chemistry}
}